Copy-line illuminator



Aug. 21, 1956 T. B. HARPER COPY-LINE ILLUMINATOR 2 Sheets-$heet 1 Filed Oct. 30, 1953 illuminated.

Thi we is INVENTOR. Toby 5. Harper After/veg 21, 1956 T. B. HARPER COPY-LINE ILLUMINATOR 2 Sheets-Sheet 2 Filed Oct. 30, 1953 INVENTOR. Toby 5. Harper 1 1'0 *mWA/M COPY-LINE ILLUMENATOR Toby B. Harper, Dolph, Ark.

Application October 30, 1953, Serial No. 389,253

6 Claims. (Cl. 240-2) This invention relates to an illuminator for use in an adjustable copyholder such as is commonly used by typists to hold a sheet of work being copied on the typewriter, and has for its primary object the provision of an illuminator which is adjustable both as to brightness and as to the width of the beam cast upon the work.

Copy-holders of the type referred to commonly have a hand or foot operated lever which shifts the copyholder upward by a distance corresponding to the width of a line of the work being copied each time the lever is manipulated. In this way, the lowest line of the work visible to the typist over a reference line or sight bar is the line being copied, and the next line can be brought into views above the sight bar at will. Lamps for such copy-holders are known which merely illuminate all the visible portion of the sheet of work being copied. My invention provides high intensity illumination for only that part of the copy-sheet which is being worked on, in other words, the last line or the last two lines. Some typists prefer to have the last two lines illuminated, probably because they read ahead, while others prefer to have only the last line illuminated. My invention provides simple and inexpensive means for adjusting the vertical width of the beam of light so that it illuminates either the last line only or the last two (or more) as desired. Even in a normally lighted oflice, the illumination on the work being copied is usually not fully adequate. By providing the additional illumination required, typists find the eye strain to be definitely less than formerly. In addition, a bright horizontal line of illumination makes the line being copied jump out at the user each time she returns her gaze to the Work, so that there is also less strain due to the eye hunting for a fraction of a second for the area being copied. I have found it very useful, in such a device, to be able to adjust the intensity of the illumination which my device casts upon the copy. This is due partly to the variations in the level of ambient illumination and partly to a matter of individual preference of the user. The illumination should be as bright as the user finds helpful, but any brightness above that level may of itself introduce strain and fatigue. The correct level varies widely with the user, and with the work being copied, and therefore, the factor of brightness adjustment is very important. I am aware that it is customary to use a voltage regulating device, such as a variable resistor in series with a lamp to control the light intensity, but this is a relatively expensive expedient and, furthermore, is not eifective in the case of fluorescent lamps which I ordinarily prefer to use as a light source, since such lamps require a definite potential for operation and will merely extinguish if the voltage level is dropped below this point. I therefore provide an adjustable shutter inside of my illuminator which can be moved to determine the amount of light which can pass from the lamp to the copy and thus adjust the brightness. Another adjustable shutter controls the beam vertical width so that by adjustment of nited States Patent 2,760,049 Patented Aug. 21, 1956 the two shutters, both the intensity and the width of the beam can be controlled.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings, in which:

Fig. 1 is a front view of a portion of a copyholder holding a sheet of work illuminated according to my invention;

Fig. 2 is an end view of the line illuminator lamp shown in Fig. 1;

Fig. 3 is a sectional view taken on line 3-3 of Fig. 1;

Fig. 4 is a view of the width adjusting shutter of the lamp shown in Fig. 3;

Figs. 5 and 6 aresectional views taken on lines 5-5 and 66 respectively of Fig. 4;

Fig. 7 is a front view of a modified form of my invention;

Fig. 8 is an end view of the lamp shown in Fig. 7;

Fig. 9 is a sectional view taken on line 9-9 of Fig. 7, and including a portion of a typical copyholder; and

Fig. 10 is a back view of a portion of the lamp shown in Fig. 7, showing the shutter hinge arrangement.

The illuminator has a casing 2 in which sits a lamp 4. This lamp is preferably a fluorescent lamp of about eight Watt size, which I have found ample for the purpose, while at the same time it consumes so little power that it does not excessively heat the casing even though no special provision is made for ventilation. It will be understood, however, that a small filament lamp could also be used, preferably of the elongated show-case type. However, a day-light eight watt fluorescent lamp has been found very satisfactory for the purpose. A separate ballast inductor 6 is required, which may be fixed to or made part of the casing, but I prefer it separate from the casing so it is shown as incorporated in an electric plug unit at the end of supply cord 10, such units being commercially available.

Casing 2 has two tightly fitting sides, 12 and 14, the construction being, of course, light-tight. A lip 16 is bent inwardly of the casing and may be struck from the same sheet of metal as the casing. Lip 16 extends only a short distance into the casing and slidably supports :a shutter 18 which is clipped onto the lip 16 by means of spring clips 20. Lugs 22 are fixed to shutter 18 near the ends thereof and are screw-threaded to receive thumb screws 24. The spring 26 around each thumb screw forces the shutter into the widest aperture position which the screw permits. By rotating thumb screws 24 the shutter can be drawn against the spring compression until the aperture is reduced to a minimum, representing the smallest inensity of illumination the device can funish. As the thumb screws are rotated in the opposite direction, the shutter aperture increases to admit more light into the chamber 28 whence it passes out after reflection from the walls of the chamber onto the surface of the copy-sheet 30. A width-adjusting shutter 32 having an outwardly bent top edge 34 is provided for adjusting the vertical width of the beam. This shutter is vertically movable with respect to casing 2 and is provided with threaded lugs 36 which receive thumb screws 38 tion. A switch 40 is provided for turning the light on and off.

The entire unit is provided with suitable fastening means such as struck-out lugs 44 for mounting the same on the sight bar 46 of a conventional copy-holder. The copyholder is of the conventional type wherein the plate 48 holding the copy sheet 30 may be moved vertically to any desired position with respect to sight bar 46. Thus, by mounting the illuminator on the sight bar, it projects a horizontally elongated area of illumination across the sheet, the vertical width of the bright area being adjustable to encompass only one line or more as desired. Fig. 7 shows an alternate means of controlling the width of the aperture provided by shutter 18a. In this case a hinged construction may be employed with two thumb screws 4811 on the ends 12a and 14a of the casing whereby the angular position of the shutter 18a is changed to control the aperture. It will be apparent that various other means for adjusting the shutter could be employed to control the intensity shutter and the width shutter.

An alternative construction of the width shutter is also shown in Figs. 710, where the width shutter 32a is hinged at 50, which may also serve as a hinge for the intensity shutter 18a. In this case, the lug 44a projects from the wall of casing 211 to support the illuminator on sight bar 46. Thumb screws 52 adjust the angular position of width shutter 32a to determine the width of the emergent beam of light. As sightbar 46 is frictionally adjustable on bail 54, it will be apparent that the angular position of the illuminator with respect to the copy can be readily adjusted.

The interior of the casing is made of good reflecting material with a mat surface so that the reflected light which emerges through the aperture is substantially uniformly distributed over the illuminated area both axially and laterally. If desired, glass bead paint such as is used for illuminated roadway signs may be employed for the interior of the casing.

Various other modifications will suggest themselves to those skilled in the art, as it will be apparent that the embodiments shown are only exemplary and that various modifications can be made in construction and arrangement within the scope of my invention as defined in the appended claims.

I claim:

1. For use with a typewriter copyholder having a sight bar adjustable step-by-step relative to the lines of a mounted piece of copy, an elongated, substantially lighttight casing having a light-reflecting interior surface and having a single narrow elongated aperture substantially coextensive with the length of the casing, an elongated lamp in said casing, an adjustable opaque barrier in said casing between said lamp and said aperture positioned to block direct passage of light from said lamp through said aperture, said lamp and said barrier being substantially coextensive in length with said casing, and means for adjusting said barrier so as to admit more or less light from said lamp to said aperture in accordance with the degree of adjustment of said barrier, and means for mounting said casing on the sight bar of a typewriter copyholder.

2. The invention according to claim 1, and further means for independently adjusting the width of the aperture so as to adjust the width of a beam of light issuing from said lamp through said aperture.

3. The invention according to claim 2, one edge of said adjustable aperture comprising one axially extending first edge of the casing, said casing extending from said first edge downwardly around said lamp and upwardly for a short distance generally toward said first edge and terminating in a piano hinge portion, a hinge pin in said hinge portion, successive portions of said hinge pin being covered by said hinge portion and other portions being exposed relative to said hinge portion; two hinged shutters mounted on said exposed portions of the hinge pin, one of said shutters being angularly adjustable adjacent said lamp to cut 01f more or less light from said lamp in accordance with the angular position of said one shutter on the hinge pin, and the other shutter extending generally towards the first edge with an elongated edge thereof parallel to said first edge, and being angularly adjustable on said hinge pin to adjust the distance of said elongated edge from said first edge to control the width of said aperture.

4. For use with a typewriter copyholder having a sight bar adjustable step-by-step relative to the lines of a mounted piece of copy; an elongated casing; means for mounting said casing on the sight bar of the typewriter copyholder; said elongated casing being substantially light-tight and having a single narrow elongated aperture substantially coextensive with the length of the casing for providing a narrow line of illuminated area; a lamp in said casing and totally enclosed thereby except for said aperture; an adjustable barrier in said casing between said lamp and said aperture, and means for adjusting said barrier to admit more or less light from said lamp to said aperture in accordance with the degree of adjustment of said barrier, said lamp and said barrier being substantially coextensive with said casing, further means for adjusting the width of said aperture so as to adjust the width of illuminated area provided, one edge of said adjustable aperture comprising one axially extending first edge of the casing, the other edge of the aperture being formed by the upper edge of a rigid sheet bent outwardly away from said casing, said width adjusting means comprising lugs fixed to said rigid sheet and extending adjacent the end walls of the casing, slots in the end walls of the casing adjacent said lugs, and fastening means extending through respective slots in engagement with said lugs for adjustably fastening said lugs in any desired position along said slots.

5. The invention according to claim 4, the other edge of said casing being bent inwardly around said lamp to form a lip partially enclosing said lamp; said barrier comprising a shutter slidably mounted on said inwardly bent lip for movement toward the opposite wall of the casing to further enclose said lamp, thereby admitting more or less light to said aperture in accordance with the position of said shutter; and means extending from said shutter exteriorly of said casing for adjusting the position of said shutter.

6. The invention according to claim 5, said exteriorly extending means comprising at least one thumb screw.

References Cited in the file of this patent UNITED STATES PATENTS 1,267,055 Cathcart May 21, 1918 1,397,803 Ensor et a1 May 22, 1921 1,406,648 Ingols Feb. 14, 1922 1,609,418 Nechamkin et al. Dec. 7, 1926 1,886,027 Klingsick Nov. 7, 1932 2,153,103 Stevens Apr. 4, 1939 2,569,078 Silver et a1 Sept. 25, 1951 

